A shock absorber is generally described as a device for absorbing sudden kinetic impulses. This absorption is accomplished by storing the energy from the kinetic impulse—typically with an elastic object, such as spring—and dissipating the stored energy by passing an object through a viscous medium, for example. The spring can be made from a variety of materials, including steel, titanium, wood, fiberglass, or carbon fiber. Alternatively, the elastic object may also be implemented as a compressible gas, such as nitrogen, in a sealed chamber. The energy dissipation, or damping, is typically achieved by moving a piston with one or more holes in it through a viscous fluid, causing fluid to flow through the holes in the piston to either side of a sealed enclosure. The kinetic “shock” is absorbed in the elastic object, such as a spring, and causes the elastic object to begin oscillating. The absorption of the shock is caused by the dissipation of this oscillation, by generating a damping force on the oscillation by passing an object through a viscous medium.
Shock absorption in RC vehicles has typically been accomplished through the use of linear dampers. Linear dampers commonly employ a spring or compressible gas that actuates a piston in a sealed chamber of fluid. The spring stores kinetic energy, and a piston dissipates the energy as it moves through the fluid.
While linear dampers are simple to manufacture, they introduce a number disadvantages, especially in RC vehicles. For optimum vehicle handling, it is advantageous to have heavy components placed close to the centerline of the vehicle. However, linear dampers and springs are often placed close to the wheels of the vehicle and far from the centerline of the vehicle, resulting in suboptimal performance. Additionally, linear dampers in open-wheeled vehicles introduce an obstruction that affects the aerodynamics of the vehicle. Furthermore, linear dampers are heavy and large, requiring compromises in the design of a vehicle's suspension, steering, chassis, and body.